There is no need to prepend PREFIX to paths in manual pages. Everything is
handled by the build system of the port.
Before:
$ grep -Z /usr/local/usr/local /usr/local/man/man5/avahi-daemon.conf.5.gz
\fB/usr/local/usr/local/etc/avahi/avahi-daemon.conf
After:
$ grep -Z /usr/local/usr/local /usr/local/man/man5/avahi-daemon.conf.5.gz
\fB/usr/local/etc/avahi/avahi-daemon.conf
Differential Revision: https://reviews.freebsd.org/D24200
cf88b9095d